Does anyone have a clear understanding of the interaction of aluminum alloys used in carabiners, belay plates etc. and climbing ropes? Specifically, what causes the dreaded “Black Rope Syndrome” (BRS)? Is it the physical abrasion properties of the weave of the rope? Is it the dry or other coatings on the rope? What gives? Over many years, I’ve had some ropes that stay fairly clean and others that have an incredible attraction for the black stuff. And, as you know, this black slime readily and quickly transfers to your hands, tape jobs and fashion clothing like cash to a dirtbag. What da hell?

In the pictures below are two of my current ropes. The top pic is a blue Mammut Infinity 9.5mm dry. The bottom pic is a Mammut Galaxy 10mm dry (was gold/tan, now ?). Both ropes are roughly the same age with the Galaxy 10mm seeing a little bit more use. The blue Infinity (and other colors of 9.5mm Infinity ropes I’ve had) stays MUCH cleaner with respect to the black stuff. The ‘gold’ Galaxy has a nasty affinity for the black stuff and kinda sucks to climb with. I’ve washed the Galaxy (and other ropes prone to BRS in the past) many times using woolite in a tub, by hand, but there never seems to be any improvement. Both ropes are 2 over 2 weave, dry coated and the same brand, so what’s the deal?

There is a ton of experience and knowledge out there in Taco land, so let’s hear what folks have to say about all this… What specifically causes BRS? Is there any way to avoid it? Are there other ropes out there besides the Mammut Infinity 9.5mm that stay devoid of BRS over time? I searched the forum and didn’t find many posts related to this, so hopefully this is a fruitful discussion. Inquiring minds want to know! Thanks!

Mammut Infinity 9.5mm - I've had 3 of these in different colors and they all stayed pretty darn clean

Credit: BrassNuts

Mammut Galaxy 10mm - I've had 3 of these over the last few years in various colors and they all have a NASTY affinity for the black stuff

I just looked at the Mammut website and they list a PTFE (Teflon) coating for the Infinity 9.5mm, but not for the Galaxy 10mm. Interesting point. I've noticed a significant difference across other brands and models of ropes historically, but I couldn't say now whether or not the better performers had PTFE coatings...

yeah maybe the teflon. my beal ice lines are teflon coated and getting to the thoroughly abused stage. never been washed but they still look good. fairly clean that is. starting to fray. been used heavily on summer rock and winter ice.

why not pose this question to mammut? send 'em an email and let us know what they say.

The black is actual aluminum particles. You can mitigate it and all but make it disappear by the use of Stainless steel (or steel) belay devices and carabiners. he only place this is practical is in toprope situations ...usually closer to the car due to the extra weight. Toperoping in particular will cause more black if you stick with alum. Otherwise, got to wash the rope. Rapping in sandstone areas with aluminum devices in the rain speeds it up due to abrasion. Dramatically. You can see it with a scouring pad and an aluminum pan. The sponge side pulls no black, whereas a piece os steel wool to clean will be black stat.

Couch beat me to it - friction between the texture of the rope weave and your aluminum devices. There may be some question around what makes some ropes seemingly retain more aluminum particles than others, but I've never had an aluminum belay device I didn't have to hit with a file or replace after awhile.

Yes, understood that the black is actual aluminum particulates, but the question is why some ropes have more of an affinity for the black stuff than others? Actual coating chemistry? Sheath weave abrasion characteristics (2 over 2 vs. 1 over 1)? It would be cool if there were more stainless steel belay plate options out there - I'd be fine with a few more ounces to at least partially rid my ropes of BRS. It also makes me wonder if there is a way that biners could be designed with a small stainless inlay in the radius to reduce the BRS contribution from that component... P.S. edit - John TP - a little bit of the discoloration of the Galaxy in the bottom pic is likely due to 2 days of sport wanking at Shelf Road this last weekend - quite the dusty venue!

How controlled is your comparison between the type of use each rope gets?

In my experience, oxided ropes was more a function of how much rappelling and lowering the rope was subjected to. At YMS, the static lines we used for guiding received tons of double break carabiner mileage and they were filthy. People I know that do more sport climbing, obviously involving much more weighted contact/abrasion with the carabiner have blacker ropes. Or so I thought.

I just figured my ropes, all of them, have never collected that black oxide because I never sport climb and rarely rappel/lower. It never occurred to me that different ropes collect or repel the oxide differently. Are you sure that's the variable (rope construction/coating) and not perhaps that the ropes in question see different kinds of action?

Sterling ropes have a similar problem. It isn't so much that the rope turns black, but that after belaying a pitch or two, your palms will get blackened.

It's like they are a carrier host of the dreaded “Black Rope Syndrome” - you can't tell from looking at a Sterling that you will soon be afflicted with BRS, but handle that rope for any amount of time and you'll see you've got BRS.

Seriously though - why would some ropes soak of the BRS, others deflect it, and yet others pass it on to the human while looking innocent and pure themselves...?

I have a formerly bright yellow Mammut Tusk 9.8 w/ Superdry that all but turned black in the first day's use. Kind of put me off of it after that and I've never really used it much. It has been used a few times since, but it got most of that lovely patina on the first day.

I've had ropes go black like that, or even worse. Hideous, at worst. Some are worse than others.

I suspected that improvements in rope technology have reached the point where the rope sheath is now can be so durable that it wears the surface off of the aluminum belay plates. But your comparison makes me think that only certain ropes do this......???? Interesting.

Last couple years, I've been using either a gri-gri or a steel belay/rappel device, made by DMM: